With the progress of computer technologies, techniques of the network communication develop vigorously. In general, terminal equipments with the network connection function, such as desktop computers, notebooks, servers, network communicational apparatuses, network switches, network connection displays, network card, and so on, have a network communication device. Therefore, the terminal equipment can communicate with other terminal equipments linking to the network by the internet through the network communication device and a network cable.
FIG. 1 is a circuit block diagram of a network communication device of the terminal equipment; and FIG. 2 is a schematic view showing a network magnetic module of the network communication device of FIG. 1. As shown in FIGS. 1 and 2, the terminal equipment 1 includes a network communication device 2, and the network communication device 2 includes a network connector 21 (i.e. Ethernet connector), a network magnetic module 22 (i.e. Ethernet transformer), and a network chip 23. The network connector is a RJ45 connector, and the network chip 23 is a Physical Layer Integrated Circuit (PHY IC). The network magnetic module 22 is electrically connected with the network connector 21 and the network chip 23, and the network magnetic module 22 is configured to perform the isolation and coupling of the signals between the external network and the network chip 23, and configured to perform the functions such as impedance match, signal shaping, common mode noise reducing and EMI reducing, and so on.
The network magnetic module 22 includes a casing 221, a plurality of ring-shaped transformers 222, and a plurality of ring-shaped filters 223. The casing 221 has an accommodation space 224, and a plurality of conductive pins 225 are extended outwardly from two exterior surfaces of the two opposite sides of the casing 221, respectively. The ring-shaped transformers 222 and the ring-shaped filters 223 are commonly disposed in the accommodation space 224 of the casing 221, and sealed in the casing 221 to form the network magnetic module 22. In the network magnetic module 22, each ring-shaped transformer 222 is electrically connected in series with a corresponding ring-shaped filter 223 via a plurality of winding coils, and each assembly of the ring-shaped transformer 222 and the ring-shaped filter 223 is connected to the conductive pins 225 on the two opposite sides of the casing 221 through two opposite ends of the winding coils. Consequently, a ring-shaped transformer 222 and a corresponding ring-shaped filter 223 can define a signal transmission channel.
Since the ring-shaped transformers 222 and the ring-shaped filters 223 of the conventional network magnetic module 22 are commonly disposed in the accommodation space 224 of the casing 221, and since the connection of the ring-shaped transformer 222 and the ring-shaped filter 223 are performed by using jump interconnection wires to couple the winding coils of the ring-shaped transformer 222 and the ring-shaped filter 223, the length of the interconnection wire between the ring-shaped transformer 222 and the ring-shaped filter 223, the distances between the interconnection wires, and the distances between the coils are quite close and can't be controlled and maintained in constant lengths. Consequently, the network communication device 2 is suffered from electromagnetic interferences when the network communication device 2 is operated. In addition, in the conventional network magnetic module 22, the signal transmission channels, which are defined by the ring-shaped transformers 222 and the ring-shaped filters 223, are integrated into a single module, and the ring-shaped transformers 222 and the ring-shaped filters 223 can't be separated from the casing 22. When the network magnetic module 22 is disposed on the circuit board, the network magnetic module 22 occupies more complete regions and spaces of the circuit board. Consequently, the layout and the arrangements of circuits, traces and electronic elements and the utilizations of the space on the circuit board are restricted. In addition, the miniaturizations of the products don't come easy.